Rear not a gentle cub from a vicious dog, much less a vicious cub from a vicious dog.

Much is not to be expected from a child of evil parents even when it shows some good qualities. What, then, can be looked for from a child of evil parents who in youth follows their example?

The serpent breeds and casts [her young] upon the inhabitants of the town
The first word is explained to mean "a bird of solitary habits." The saying is descriptive of parents who neglect their children so that they become a public charge.